Prism4Free
Contributors: Pancakes
Prism Launcher does not allow you to create an offline account without having a Mojang / Microsoft account. If you click the "Add Offline" button, you will be presented with this error.
You can bypass it with a patched executable. This is better than other cracked forks because you're still running the official Prism Launcher only the executable is patched; everything else remains untouched.
Please close Prism Launcher before starting. If it's open, please close it. You will need to (re)open it only in the end.
Methods
Method 1 - Download from a repo that already publishes releases
Go to this repo's latest release and scroll down until you see "Assets". Expand it if collapsed, then download the file relevant to your system: Windows = PrismLauncher.exe, Linux / Steam Deck = the .AppImage, macOS = the .dmg (the easy one). The bare prismlauncher-macos file is for the advanced swap route; it is not needed for a normal install.
Method 2 - Create your own repo and patch the executable yourself
You can patch the executable by yourself; your own repo, your own builds, no trusting anyone else's files. Read more here.
Windows
After downloading PrismLauncher.exe from the repo, open Prism Launcher's folder. Paste this into the File Explorer address bar (the bar at the top) and press Enter. It takes you straight to the folder where prismlauncher.exe is:
That is the default folder the official installer uses. If you use a portable copy, it is wherever you unzipped it. (Do NOT confuse this with %AppData%\PrismLauncher; that folder holds your accounts and instances, not the exe.)
Now:
- Keep a copy of the original; rename
prismlauncher.exetoprismlauncher.exe.bak(or anything you like). - Replace the stock
prismlauncher.exe(the folder's shortcuts and the updater's backup logic point to this executable) with the patched exe you downloaded. - Launch Prism Launcher, click the Accounts button at the top right.
- Click "Add Offline", type in the username you want and enjoy playing Minecraft without Mojang or Microsoft accounts, using Prism Launcher.
Every time Prism Launcher updates, you have to patch the executable again with either of the above methods; download the official update first, then re-apply the patched file.
Linux / Steam Deck
On Linux, Prism Launcher is a single self-contained .AppImage file, so this is even easier than Windows: one file swapped for another. There is no install folder, the AppImage is the install. Your instances, settings, and accounts live in ~/.local/share/PrismLauncher, and this swap never touches them.
This requires the AppImage and does not work with Flatpak.
- Download and run the official AppImage from Prism Launcher to create all the necessary files and folders. Rename the file to
PrismLauncher-Linux-x86_64.AppImage.bak(or anything you like). If double-clicking the AppImage does nothing, your browser stripped the executable bit. Right-click it, then click on Properties and then click on Permissions and tick "Allow executing file as program" or simply runchmod +x ~/Applications/PrismLauncher-Linux-x86_64.AppImage. - Download
PrismLauncher-Linux-x86_64.AppImagefrom the repo and move it to the location of the official AppImage; keeping the same file name is what keeps existing menu entries, desktop shortcuts, and Steam links pointing at the right file. (You can also keep both side by side under different names if you'd rather.)
- Launch it and click the "Accounts" button at the top right.
- Click "Add Offline", type in the username you want and enjoy playing Minecraft without Mojang or Microsoft accounts, using Prism Launcher.
The following works on paper, not tested
Steam Deck: switch to desktop mode and follow the steps above exactly; ~/Applications works well. To get it into your library, right-click the AppImage in Dolphin then click Add to Steam. Desktop mode only; never gaming mode.
Every future update on Linux is one-file swap; the AppImage carries its own Qt runtime. One exception: if your launcher is the Flathub / Flatpak version, this file swap does not apply to it (Flatpak bundles its own launcher inside a sandbox); use the AppImage route instead.
macOS
Requires screenshots and testing. The repo generates for macOS as well
Why?
Instead of downloading third-party forks, you can just use Prism Launcher directly. The whole difference between the official exe and the patched one is four small patches:
001 - offline account creation - removes the error in the screenshot at the top. You can click "Add Offline" and make an offline account without any Microsoft / Mojang account. That check ran entirely inside the launcher; it never contacted Microsoft.
002 - offline launching - when you launch with an offline account picked, the "you must have a Microsoft account" popup is skipped and the game starts normally instead of demo mode. Also, if every account in your list is offline, the "Download All" button works again, and the first-run "Add Microsoft account" wizard page is skipped.
003 - account picker - if no account is picked for the launch and every account in your list is offline, instead of the Microsoft nag, you get the normal account picker; just choose who to launch with."
004 - auto-fetch on launch - if the game files (libraries, etc.) are missing and every account in your list is offline, the launcher downloads them itself and then starts the game. These are the same public files an online launch downloads anyway.
Want more detail? Read the advanced notes and the /patches folder in the repo; every release also ships the exact patch text as source-patches-<version>.patch, so you can always see 100% of what was changed.